Animal Reference

The impala

21 November 2013

The impala epitomizes the open woodlands of South Africa. The explorer Lichtenstein first described the impala as Antilope melampus in 1812 based on a specimen from near Kuruman in the Northern Cape. Its name was changed to Aepyceros melampus by Sundevall in 1847 because Antilope only occurs in India. The impala occurs as six subspecies in southern, central and eastern Africa, with Aepyceros melampus melampus in the Waterberg region and elsewhere in South Africa.

The common name impala is derived from its izulu name impala. Although not a gazelle, the impala is a slender antilope of medium size. Only the rams carry lyre-shaped horns, the length and shape of which is used to determine age. The horns remain straight up to an age of 22 months, then first start to turn backwards before the tips turn forward at 27 months of age. An adult ram weighs around 54 kg and an ewe 41 kg, but the rams from the south-western Limpopo province in South Africa and East Africa are heavier. The adult ram has a shoulder height of around 91 cm and the ewe one of 89 cm. The impala has triangular hair with blunt edges. The shiny upper coat and flanks are brownish-red, but on the lower flanks and behind the shoulders it is pale brown. The belly is white and the impala has white patches above the eyes. The metatarsal glands above the hooves occur in a prominent black hair cluster on each hind leg.

The impala is a mixed feeder that feeds on grass and flowers in the wet season and leaves in the dry season. The habitat is open woodland and it avoids grasslands, wetlands and mountainous regions, not normally occurring higher than 1400 m above sea level. The rams are territorial and impalas generally do not occur more than 1 to 2 km away from water. An impala eats around 0.9 kg of dry plant matter per day in the dry season and 1.9 kg per day in the wet season, and drinks around 2.5 litres of water per day. They have a preference for natural waterholes and usually occur near waterholes such as Fish Eagle or Nkwe on Shayamanzi.

The impala’s breeding herd usually includes 6 to 20 animals but it can be much more. These are also bachelor herds of 6 to 7 animals. A breeding herd has a range of around 80 to 180 ha. Breeding occurs mainly in the autumn and a ram can fertilize up to 15 ewes per breeding season. The embryo implants only in the right horn of the uterus and the gestation period lasts from 194 to 200 days. A single lamb weighing 4.5 to 5 kg is born in seclusion but joins the herd after a day or two. While population growth can be as high as 48% in areas receiving more than 600 mm of rain per year, it is only 11.6% in the Kruger National Park with its many large predators. Especially spotted hyaenas kill up to 80% of the impala lambs there per year. The longevity of an impala in the wild is around 15 years.